1. Field of the Invention
This invention generally relates to mechanical lifting devices, and particularly to a lifting device which can be used by one man for lifting and moving heavy and bulky items safely, substantially independently of the shape, size or weight of the item being lifted.
2. Description of the Prior Art
In lifting and/or moving an item, due consideration must be given to its size, shape and weight. One or more of these factors may be crucial in determining whether one or more individuals must be used to lift and/or move an item, particularly in the field, such as at a construction site. For example, at highway construction sites, various barriers must continuously be moved to divert vehicular traffic to detour around the areas of construction to provide for the safety of the workers and for the safe operation of equipment. As highway construction progresses, the barriers must be moved to the next succeeding construction zone. The barriers which are used vary and may include concrete median barriers, steel median barriers and/or sand-filled plastic modules--sometimes referred to as "sacrificial crash cushions" or "inertial barriers". All of these barriers are large, heavy and bulky and cannot be conveniently lifted or moved by a single individual. Even when mechanical hoisting equipment is utilized, frequently more than one individual must be used to secure the barriers and safely lift and move the barriers since the accidental dropping of most barriers, particularly the concrete median barriers and the sand filled crash cushion barriers, can cause damage, be rendered useless if dropped and, of course, can cause injury to personnel.
The devices which have been used to date to move large, heavy and/or bulky items, particularly in the field, have been unsatisfactory either because they were not universal and were specifically designed only to lift and/or move a particular item; they required more than one individual to use; they were cumbersome and inconvenient to use; and/or they did not provide the degree of safety to personnel, equipment and/or the items that were being lifted and moved.